Spectroscopic analyses of PVDX (X = F, Cl and Br)

Abstract

In the present work polyvinylidene fluoride PVDF was subjected to Fourier Transform Infrared (FTIR) analyses to assign its bands. A model molecule consisting of 14 units of PVDX (X = F, Cl and Br) has been utilized to studies its geometrical, physical and spectral features. Results show an increase in the final heat of formation, enthalpy, entropy and heat capacity and a decrease in free energy with increasing temperature. Band gap energy of studied structure was calculated at PM3 semiemperical quantum mechanical method. PVDF shows the highest band gab energy. Higher level of theory at Hartree-Fock (HF/3-21g*) was conducted for comparison. As Cl and Br substituted F shifts, in band positions took place while molecular dimensions remains the same. Results indicate that, semiemperical methods provide comparable physical data and vibrational assignment; band positions are not close to experimental results due to the absence of electron correlation in the semiemperical quantum mechanical methods. Copyright © 2014 American Scientific Publishers All rights reserved.